From 8eea66b8bb5832ec1a765a3bade4fd26030fe351 Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Sat, 16 Nov 2019 12:41:13 +0100
Subject: [PATCH] clone.2: Check for MAP_FAILED not NULL on mmap()

If mmap() fails it will return MAP_FAILED which according to the manpage
is (void *)-1 not NULL.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
---
 man2/clone.2 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/man2/clone.2 b/man2/clone.2
index 57a9eaba77..faff2ada68 100644
--- a/man2/clone.2
+++ b/man2/clone.2
@@ -1628,7 +1628,7 @@ main(int argc, char *argv[])
 
     stack = mmap(NULL, STACK_SIZE, PROT_READ | PROT_WRITE,
                  MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, \-1, 0);
-    if (stack == NULL)
+    if (stack == MAP_FAILED)
         errExit("mmap");
 
     stackTop = stack + STACK_SIZE;  /* Assume stack grows downward */
-- 
2.47.3